CENTRIFUGAL DEVICE FOR INCREASED PREFORMS AND ALIGNED SECTIONS SEC U ENCIALLY
Field of the Invention The present invention relates generally to the field of the feeding of preforms in facilities for the manufacture of containers of thermoplastic materials, particularly by means of blow molding or blowing of hot preforms and refers more specifically to the improvements provided. to the centrifugal devices for feeding preforms of thermoplastic material lying down and aligned from preforms received on rail, the device comprises: an essentially horizontal conveyor ring that rotates about an axis; a rotating central disk that rotates around the same direction as the ring and the axis inclined in relation to that of the ring; the disc and the ring are separated from each other in a bulk loading area of preforms on the disc and which is essentially tangential in a transfer zone of the disc preforms on the ring located at a level higher than that of the disc area. load; a lateral guide that rotates peripherally to the ring to retain the preforms transferred on the ring, and
an outlet channel open towards the peripheral guide and extends essentially tangentially to the ring for the evacuation of the lying and aligned preforms. BACKGROUND OF THE INVENTION Users of manufacturing facilities for containers of thermoplastic material in particular for blowing or stretch blowing hot preforms have higher production rates. Manufacturing rates of an order of magnitude of 40,000 containers per hour are currently common, and according to user requirements, the studies are oriented to the maintenance of higher rates in the order of 60000 to 80000 containers per hour. Regarding the feeding of the preforms in the installations of this type, the common facilities with elevator, with a high hopper and a slide of feeding the preforms by means of gravity at the entrance of the facilities can provide satisfaction for the cadences that are currently practiced but can not support the clearly higher cadences that are expected. In addition, the current feeding devices have significant heights that not only require the installations to be installed at high height and by. Therefore, they are more expensive, but they need important material accessories (access stairs, walkways, fences, ...) that are adequate to take care of the safety of the personnel that is going to
work in the high parts. The current studies are therefore oriented to ground feeding devices, preferably to the height of the human waist, so as to facilitate handling and monitoring during operation. Thus, centrifugal feeding devices of the aforementioned type can be developed, also devices with a rotary cavity due to their general conformation that have a low height and that allow the preform to be fed into essentially horizontal conveyors with parallel filaments or bands. An important problem that the preform feeding devices must solve is the need to eliminate the undesirable preforms, that is to say in particular the preforms outside the standards that do not belong to the treated type and that present in particular a diameter and / or a different length of these two treated preforms, the packaged preforms (which can be assimilated into a preform of excessive length), etc. The elimination of these undesirable preforms is of extreme importance since if they are introduced in the container manufacturing facility, they can cause considerable damage to the installation, until the partial destruction of them with immobilization times and the inherent financial losses for the readjustment and / or the reconstruction of the damaged parts. Different systems of elimination of the
undesirable preforms adapted for feeding devices currently used in common, but those currently used feeding systems are not transportable, at least in a simple way, in the context of centrifugal feeding devices. Brief Description of the Invention The invention aims to respond to this attempt and to propose improved means for eliminating undesirable preforms in the centrifugal feeding devices, the means to the maximum extent possible being structurally simple and easy to manufacture and put in practice, with a great speed of operation so that they are suitable to be satisfactory under very high manufacturing rates, and which do not require substantial modifications in the design and operation of the centrifugal feeding device. For this purpose the invention proposes a centrifugal device for feeding preforms of thermoplastic material, lying down and aligned from preforms received in bulk as mentioned above, a device that being formed according to the invention is characterized in that it also comprises: a mobile organ mounted on the lateral guide later (considered in the direction of rotation of the transport ring) of the transfer zone and before the opening of the exit channel and appropriate to occupy a rest position in which it does not
it affects the displacement of the participating preforms by means of the conveyor belt and an operational position in which the preforms have to leave the conveyor ring. - drive means operatively associated with the movable member to selectively cause its movement between these two resting and operational positions, etc. detecting means located before the non-movable body and suitable for detecting an undesirable preform present on the conveyor ring, the detection means are functionally connected to the means of driving the movable member so that each time an undesirable preform is detected, actuate the movable member in its proper operational position for the ejection of the undesirable preform. The proposed system according to the invention can give rise to two main modes of realization according to which the undesirable preform is expelled towards the outside and is evacuated or it is expelled towards the interior and it is sent back to the rotary cavity to be reinserted in the batch of preforms that are going to be treated. Thus, in a first possible embodiment, it is proposed: that the mobile element be a mobile trapdoor and therefore advantageously displaceable, in particular pivoting towards the outside
of the lateral guide, which is suitable for closing at least partially an opening made in the lateral guide and that the driving means are suitable for moving the hatch under the order of the detection means and opening the side guide opening in such a way that the undesirable preform detected is expelled through the opening under the action of the centrifugal force. Such a device is suitable for the final elimination of the undesirable preforms, in particular the preforms accumulated tightly, the preforms that do not comply with the standards (diameter and / or length different from those of the preforms to be treated, preforms that have defects, etc.) In any case with respect to the high speed of operation of the feeding device and in the times necessary for the hatch to work, it is possible that if the preforms are very close to each other on the conveyor ring that not only an undesirable preform is expelled by the trapdoor, but also the following preform, and some subsequent preforms that follow them and that do not have to be ejected. Resulting in an elimination of preforms in good condition, and to avoid a loss the need to manually sort the batch of preforms removed to recover the correct preforms and put them in the circuit. In an embodiment of that type, it is interesting that the device also presents:
an auxiliary mobile finger disposed before the hatch and suitable for occupying a displaced position in which it no longer interrupts the path of the preforms in the conveyor ring and an ejection position in which it is interposed to the path of the preforms towards the inside on the rotary disk, and means for actuating the mobile finger appropriate to move it to occupy one or the other of the two mentioned positions, said driving means are placed under the dependence of the detection means in such a way that the moving finger and either in its position displaced from the passage of the undesirable preform detected and this in its ejection position in the passage of at least the first preform next to the undesirable preform detected to rest on the inside of the rotating disc to the first preform. Thanks to this optional arrangement, it is avoided that the acceptable preforms are evacuated to the outside, and have to be forwarded to the rotary cavity, it maintains them in the circuit of preforms to be treated and its treatment is not delayed. In another possible embodiment, it is provided that the movable member is a movable finger disposed in front of the transfer zone and is suitable to occupy, under the action of the actuating means, a displaced position in which it does not engage with the movable member. the trajectory of the preform on the conveyor ring and an ejection position in which it engages with the path of the preforms in the conveyor ring and reject the preforms
inwards on the rotating disk. A device is suitable when the defect that makes the preform undesirable is only temporary and is not intrinsic and can be repaired, for example, under the action of a shock, for example the shock suffered when the preform hits the cavity. rotary This device is particularly suitable for preforms accumulated in a non-tight manner, this means that the preforms have geometries such that one's body can be introduced into the body of the other without contact and therefore without being close to each other; Just make them fall back into the cavity to separate them. Such a device avoids, even without manual intervention, evacuating to the outside and therefore definitely the preforms that can accordingly be treated after the elimination of the factor that provisionally makes them undesirable. Therefore, as regards the packaged preforms more particularly, it is understood that the fact that they preform are closely accumulated or not, is based essentially on the geometry of their conformation, and above all on the geometry of the conformation of their body. But users of thermoplastic container manufacturing facilities demand a wide universality of operation, this means that the facilities are capable of manufacturing various containers from different preforms in certain types
they can result in tight accumulations while other types can result in unclogged accumulations. In this way it may be necessary to achieve the universality of the operation of the feeding device according to the invention, which are equipped together with two aforementioned ejection devices, that is to say a mobile hatch according to any of the provisions set forth above and of a moving finger according to the arrangements set forth below, whereby the user has the option of selecting between removing the undesirable preforms outwards through the side guide hole or inwardly on the rotating disk.
In this case, it is possible that the mobile finger is arranged in front of the mobile hatch. According to this it may be more interesting that the mobile finger is disposed in front of the mobile hatch and thus it is possible to simplify the structure by providing that the mobile finger is disposed before the mobile hatch and is confused with the mobile finger to the auxiliary ejection of at least the first preform subsequent to the undesirable preform detected while the mobile flap is in operation; the means of actuation of the finger are therefore adapted to the type of expulsion towards the outside in conjunction with the trapdoor or towards the interior. In another variant embodiment that leads to a simplification of the structure, it can be carried out in such a way that the movable flap is shaped to be able to be displaced from one position to the other from its rest position in order to assume the function of the
mobile finger The arrangements according to the invention which are to be set forth are structurally simple and do not require major modifications in the general conformation of the feeding device; In this way they are relatively inexpensive to perform while they are particularly effective or reliable. In particular, they offer the advantage of a fully automatic selection without stopping the rotary disk, and that can operate efficiently at the high speeds demanded today by installations with high production rates. Brief Description of the Drawings The invention will be better understood with the following detailed reading of certain preferred embodiments given solely by way of limiting examples. In this description, reference is made to the accompanying drawings in which: Figure 1 is a schematic perspective view of a centrifugal device for feeding preforms of the type that the invention wishes to perfect, Figure 2 is a schematic perspective view of a substantial portion of the centrifugal feed device of Figure 1 equipped with the adaptations according to the invention, Figure 3 is an enlarged view of a portion of the centrifugal feed device of Figure 2 which shows a First embodiment according to the invention, Figure 4 is an enlarged view of a part of the
Centrifugal feeding device of Figure 2 showing a second embodiment according to the invention. Detailed Description of the Invention Figure 1 shows a schematic representation of a centrifugal device, designated as a whole with the reference numeral 1, for feeding preforms 2 of thermoplastic material such as PET, of a material such that the preforms 2 received in bulk in the device (preforms 2a in figure 1) are sent to the output of the device, lying down and aligned with each other (preforms 2b in figure 1). The device has in particular: essentially horizontal conveyor ring 3 which rotates about an axis (5) (arrow 4) which is essentially vertical, a central rotary disc 6 arranged inside the conveyor 3 ring and rotates (arrow 7) in in the same direction as the conveyor ring 3 and the inclined axis 8 (typically of the order of 1 0 °) in relation to the axis 5 of the conveyor ring, the rotation speed of the disc 6 is preferably a little lower than that of the ring conveyor 3, discharge means 9 suitable for supplying in bulk the preforms 2 on the disc 6, discharge means which can be of any suitable type for moving preforms in the required quantity, the disc 6 and the conveyor ring 3 are separated between yes
in a zone 10 of the bulk load of the preforms 2a on the disc 6 and are essentially sensitive in a transfer zone 1 1 of preforms 2a of the disc 6 on the conveyor ring 3 located at a level higher than that of the zone of loading 10, a lateral guide 1 2 that rotates peripherally to the conveyor ring 2 to retain the preforms 2b transferred in the transfer zone 1 1 from the disk 6 on the conveyor 3, and - an open exit channel 1 3 in the peripheral guide 1 2 and extends essentially tangentially of the conveyor belt 3 for the evacuation of the preforms 2b lying and sequentially aligned with each other. Although this is not imperative, in the preferred relationship mode illustrated in FIG. 1, the disk 6 is inscribed in the circle formed by the vertical projection of the conveyor ring 3, this means that it occupies the entire surface covered by the ring 3. The preforms 2a are poured in gage for the discharge means 9 that fall on the discs 6 at any point, for example close to the center as illustrated (arrow A), then move by gravity due to the inclination of the disc 7, sliding towards the loading zone 1 0 (arrow B) or embedding against the wall 14 that delimits it, beginning to be put into rotation by means of the disc 6. There the disc 6 moves them to a wedge
circular along the wall 14, sticking along this wall 14 under the action of centrifugal force. Arriving in the loading zone 1 1 or the edge of the disc 6 tangent to the conveyor 3, the preforms 2a, under the action of the centrifugal force pass over the conveyor ring 3 which places them along the lateral guide 1 2 During this displacement, the preforms 2b are kept positioned along the lateral guide 1 2 under the action of the centrifugal force. Finally, the preforms 2b lying down and aligned sequentially with each other are introduced by the conveyor ring 3 to an inlet of the outlet channel 1 3 or are recovered by other means of movement. It should be noted that the centrifugal device 1 for feeding preforms 2b lying and sequentially aligned with one another to be briefly described, also known as a rotary cavity feeding device, is known to transport the preforms in a lying position and aligned sequentially with each other, but no specific orientation of the preforms from the front to the rear; the preforms thus are transferred regardless of their position with each other. To now set forth the provisions that the invention proposes to introduce into the device of Figure 1 for the purpose of eliminating the undesirable preforms, we will refer to Figure 2 which reproduces the general system of the device of Figure 1 with the exception of the means of discharge 9 that although they are present
(as shown with the arrow A left in that place), they are not represented in order to leave the place for the representation of the supplementary means necessary to carry out the invention. In order to proceed with the elimination of the undesirable preforms (dented preforms, non-standard preforms, malformed preforms, etc.), the centrifugal feeding device 1 has, as shown in FIG. 2: a mobile element 1 5 mounted on the lateral guide 1 2 forward (considered in the direction 4 of rotation of the conveyor ring 3) of the transfer zone 1 1 and before the opening of the exit channel 1 3 and can occupy a • rest position in which it is affected by the displacement of preforms 2b received by the conveyor 3 in which particularly the continuity of the surface is assured with the lateral guide 1 2, and • an operational position in which the preforms 2b pass to its right so that the conveyor ring 3 ejects them towards the outside of the device (arrow 16) or towards the interior of the device (arrow 1 7), driving means 18 operatively associated with the mobile element 1 5 to selectively cause its displacement between its two resting and operational positions, and - detection means 1 9 located forward of the moving member
14, but before the loading zone 1 1 and preferably not far from it, and that it is proposed to detect an undesirable preform present on the conveyor ring 3, the detection means 1 9 are functionally connected to the drive means 18 on the movable member 1 5 so that when an undesirable preform is detected, actuate the movable member 1 5 in its proper operating position to cause ejection of the undesirable preform Due to the presence of the side guide 1 2, the detection means 1 9 they must be arranged so that their operation is not disturbed by the presence of the lateral guide 1 2; In a practical manner, the detection means 1 9 are located above the conveyor ring 3 and essentially in a balanced manner or are even moved towards the center of the device above the disk 6 with an oblique objective line. Alternatively, the detection means can be placed on a lateral guide 12 (this embodiment is not shown in the attached drawings). Considering the relatively high speed of rotation of the conveyor ring 3, the times available for the positioning of the mobile member 1 5 from the moment in which the detecting means 19 have detected an undesirable preform, it is necessary to arrange the actuating means 1 8 a the shortest response times and make the mobile element 1 5 as short as possible. The detection means 1 9 can be of any type
appropriate according to the criteria or elimination considered: for example the detection of a dimension of the preforms (typically the length and / or the transverse dimension of the preforms), detection of the distance between two consecutive preforms, detection of the profile of the preforms that seems to be the most interesting solution since it is the one that provides the most complete information appropriate to cover several of the selection criteria. The dispositions that are to be exposed can give rise to two main embodiments according to the outward direction (arrow 1 6) or towards the interior (arrow 1 7) of the ejection of the undesirable preforms. A first possible embodiment is illustrated schematically in figure 3 which is a partial view of the conveyor ring 3, the rest of the device is not reproduced since it is identical to that shown in figures 1 and 2. In this system the moving member 1 5 is constituted by a lateral guiding section 12 formed as a flap 20 displaceable preferably towards the outside and suitable for closing an opening 21 made in the side guide 1 2. More specifically in a preferred embodiment illustrated in the figure 3, the movable flap 20 can rotate outwards (double arrow 23) around a hinge 22 on one side of the aperture 21. The opening 21 and the flap 20 must have a length at least equal to and preferably substantially greater than the length of the largest preform to be eliminated; in particular performing the elimination of the preforms 2c that are
find them together, has actuating means 1 8 that open the trapdoor (in dotted lines on Figure 3). With respect to the relatively high speed of the rotation of the conveyor ring 3, the preforms are pushed towards the lateral guide 12 under the action of the centrifugal force; While the flap 20 opens in synchrony when a preform is detected by the means 1 9, the undesirable preform 2c, which no longer finds radial support when passing in front of the opening 21, is expelled through it towards the outside of the device (arrow 1 6). Taking into account the relatively high speed of rotation of the conveyor ring 3, it is possible that the preform 2b which serves the undesirable preform 2c which is ejected through the opening 21 is presented ahead of that opening while the trapdoor is still not it has been closed again. In this way, in particular by the high cadences with the preforms 2b that are presented very closely, one or more of the non-undesirable preforms 2b that follow an undesirable preform 3c have the danger of being erroneously ejected from the device, which represents a useless loss. In order to avoid having to proceed to a manual selection between the extruded preforms to recover the valid preforms, it is proposed to build the centrifugal feed device 1 in the manner shown in FIG. 4. An auxiliary mobile finger 24 is provided before the trap door 20 and shaped to selectively occupy a displaced position or rest position (for
example in the continuity of the side guide 1 2, shown with solid lines in Figure 4) and an operational position in which it extends through at least a part of the conveyor ring 3 (in dotted lines on Figure 4 ) in such a way that it intervenes in the path of the preforms on the conveyor ring and rejects those that occur inside the device or those that collide with the rotating disc 5. The auxiliary mobile finger 24 can advantageously be constituted of simple form in the form of a lateral guide branch 1 2 which can be displaced, preferably rotatably around a hinge 25 arranged forward on one side. The auxiliary mobile finger 24 is moved by the driving means 1 9 commanded by the detection means 19 in synchrony with the flap 20. Thanks to this conformation, it is avoided that the suitable preforms are ejected from the centrifugal feeding device and the deviated preforms by the auxiliary mobile finger 24 they are returned to the circuit.
The devices to be described with respect to figures 3 and 4 are clearly intended for the elimination of accumulated preforms in such a way that they are equally suitable for eliminating the undesirable preforms based on other criteria as indicated above. In addition, if certain preforms (for example preforms with cylindrical bodies with essentially the same diameter as the neck) have a geometry such that their accumulation is a close accumulation and must be eliminated from the installation, there are preforms (for example preforms) with
bodies with a diameter significantly lower than that of your neck) that can be coupled together without being a tight accumulation (not tight accumulation): the separation of two preforms thus coupled to each other with a non-tight accumulation is easy (It can suffer a simple shock) and should not be eliminated. To deal more specifically with the problem proposed by a second possible embodiment of the inventive arrangements, schematically illustrated in FIG. 3 is a partial view of the conveyor ring 3. The mobile member 1 5 is a mobile finger 27 arranged below the transfer zone 1 1 and is suitable to selectively occupy, under the action of the actuation means 1 8, a displaced position or rest position (for example in the continuity of the lateral guide 12, shown with continuous lines in FIG. 5) in which it no longer engages with the path of the preforms on the conveyor ring 3 and an operation position or ejection position in which it engages with the path of the preforms on the conveyor ring 3 and the rejects into the rotating disk 6. When hitting the rotary disk 6, the preforms 2 accumulated tightly separate under the action of shock. The mobile finger 27 can advantageously be constituted in a simple manner in the form of a lateral guide branch 1 2 which is displaceable, preferably rotary (double arrow 29) around a hinge 29 disposed in front of one side.
The users of the facilities for the manufacture of containers of thermoplastic material, clearly in PET, by means of blowing or stretch-blow molding of preforms, need their facilities to have a wide universality of operation and, in particular, serve to produce very different types of products. part of preforms of very different types. In particular, they may need that the facilities serve to indifferently selectively treat preforms with geometries that favor tight accumulations and preforms that lead to non-tight accumulations. Under these conditions, it is necessary that the centrifugal feeding device of preforms be suitable for efficiently treats the two types of preforms. For this purpose it can be conceived that the centrifugal preform feeding device combines the dispositions characterizing the two embodiments described above with respect to Figure 3 (or its variant of Figure 4) and Figure 5. The user Now select the operating mode of the device according to the type of preforms in question. Although in such a system, the position of the mobile finger 27 is different from the point of view of the functions of ensuring that this finger can be placed perfectly in front of the mobile hatch 20, a simplification of the structure in this way It could be obtained by placing the mobile finger 27 in front of the flap 20. In this case, the mobile finger 27 can also assume the role of auxiliary mobile finger 24 mentioned above in the embodiment
Fig. 4. It allows to adapt the control command of this single finger to the selected ejection mode, towards the outside or towards the interior of the device. Another variant of realization, interesting for the reduction of the number of pieces used (moving pieces and means of retention) and by the structural simplification that results, consists of making a single mobile flap suitable to selectively assume the role of the flap 20 of the first previous embodiment and the role of the moving finger 27 of the second previous embodiment. It is sufficient that the flap 20 of the first embodiment is suitable to be selectively placed in a rest position or in a displaced position under the action in the proper direction of the actuation means 1 8, which for this purpose can receive a preselection command of operation.